23-8
MCF5272 User’s Manual
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
AC Electrical Specifications
PRELIMINAR
Y
NOTE:
Above 48 MHz, the memory bus may need to be configured for
one wait state. It is the responsibility of the user to determine
the actual frequency at which to insert a wait state since this
depends on the access time of SRAM or SDRAM used in a
particular system implementation.
Wait states are inserted for SRAM accesses by programming
bits 6–2 of the chip select option registers.
A wait state is added for SDRAM read accesses by setting bit
4 of the SDRAM control register.
Read/write SRAM bus timings listed in Table 23-8 are shown in Figure 23-3, Figure 23-4,
Figure 23-5, and Figure 23-6.
Table 23-8. Processor Bus Output Timing Specifications
Name
Characteristic
1
1
All timing references to SDCLK are given to its rising edge when bit 3 of the SDRAM control register is 0.
0–66 MHz
Unit
Min
Max
Control Outputs
B6a
SDCLK to chip selects (CS[6:0]) valid
—
11
nS
B6b
SDCLK to byte enables (BS[3:0]) valid
—
8.5
nS
B6c
SDCLK to output enable (OE) valid
—
8.5
nS
B6d
SDCLK to write enable (R/W) valid
—
8
nS
B6e
SDCLK to reset output (RSTO) valid
—
7.4
nS
B7a
SDCLK to control output (CS[6:0], OE) invalid (output hold)
2
—
nS
B7b
SDCLK to control output (BS[3:0], R/W) invalid (output hold)
1.5
—
nS
B7c
SDCLK to reset output (RSTO) invalid (output hold)
4
—
nS
Address and Attribute Outputs
B8
SDCLK to address (A[22:0]) valid
—
8.5
nS
B9
SDCLK to address (A[22:0]) invalid (output hold)
2.5
—
nS
Data Outputs
B11
SDCLK to data output (D[31:0]) valid
—
11
nS
B12
2
2
Data output is held valid for one CPU clock period after deassertion of BS[3:0]
SDCLK to data output (D[31:0]) invalid (output hold)
1
—
nS
B13
SDCLK to data output (D[31:0]) high impedance
—
6
nS
Summary of Contents for DigitalDNA ColdFire MCF5272
Page 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Page 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Page 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Page 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Page 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Page 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Page 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Page 338: ...13 44 MCF5272 User s Manual Application Examples ...
Page 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Page 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Page 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Page 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...